[多媒体] VB视频调用问题

在VB里面我用capCreateCaptureWindow函数可以调用笔记本自带的摄像头，但是现在需要调用外来视频源（比如USB的视频），请问该怎么修改参数？或是要用其它的什么函数？哪位同仁知道拜托啦，急！

函数capCreateCaptureWindow的完整声明如下：
Private Declare Function capCreateCaptureWindow Lib "avicap32.dll" Alias "capCreateCaptureWindowA" (ByVal lpszWindowName As String, _
ByVal dwStyle As Long, ByVal X As Long, ByVal Y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hwndParent As Long, ByVal nID As Long) As Long